Analysis of Polycyclic Aromatic Hydrocarbon (PAH) Mixtures Using Diffusion-Ordered NMR Spectroscopy and Adsorption by Powdered Activated Carbon and Biochar

Abstract

Analysis of polycyclic aromatic hydrocarbons (PAHs) in air and water sources is a key part of environmental chemistry research, since most PAHs are well known to be associated with negative health impacts on humans. This study explores an approach for analyzing PAH mixtures with advanced nuclear magnetic resonance (NMR) spectroscopic techniques including high-resolution one-dimensional (1D) NMR spectroscopy and diffusion-ordered NMR spectroscopy (DOSY NMR). With this method, different kinds of PAHs can be detected and differentiated from a mixture with high resolution. The adsorption process of PAH mixtures by PAC and biochar was studied to understand the mechanism and assess the method.

Investigation of the Interaction of Benzo(a)Pyrene and Fluoranthene with Cucurbit[n]urils (n = 6–8): Experimental and Molecular Dynamic Study

“…The 1 H NMR of pure fluoranthene (FLT) exhibited five different aromatic peaks that were in good agreement with the documented values, ranging from 8.143 ppm to 7.438 ppm, which were shifted upon addition of the three hosts ( Figure 7 ), giving evidence to support complexation [ 47 ]. It is worth mentioning here that FLT is a non-alternate aromatic hydrocarbon-containing angle strain that has different physicochemical behavior from an alternant one [ 48 ].…”

Immobilizing a π-Conjugated Catecholato Framework on Surfaces of SiO2 Insulator Films via a One-Atom Anchor of a Platinum Metal Center to Modulate Organic Transistor Performance

“…This originated from the increase in the ring current effects on the protons of the Cat ring. Such current effects upon π-extension were also observed for the proton signals of the Cat moiety in Pd diimine complexes and polycyclic aromatic hydrocarbons …”

“…Such current effects upon π-extension were also observed for the proton signals of the Cat moiety in Pd diimine complexes 25b and polycyclic aromatic hydrocarbons. 33 Single crystals of 2 were grown by slow evaporation from an acetone solution of 2 and then subjected to X-ray diffraction (XRD) analysis (Figure 3 and Tables S1 and S2). The soft sulfur atoms of the DMSO ligands coordinated to the soft Pt(II) center.…”

Characterization of Biomass Pyrolysis Oils by Diffusion Ordered NMR Spectroscopy

“…The presence of signals resonating near ∼8 ppm and above are indicative of polyaromatic hydrocarbons . For example, the peaks at ∼8.5, ∼7.9, and ∼7.4 ppm, with a diffusivity of 10.0 D (estimated MW 230 Da), can be given a tentative assignment as a three ring PAH (e.g., anthracene or phenanthrene, 178 Da) . The peak at ∼8.5 is not visible in the 2D diffusion plot (Figure ) because it is smaller than the contouring levels used to display the plot, but it is readily observed at 10.0 D when contoured at lower levels as well as in the raw exponential fit data (Table S3); it is also observed in the 1D- 1 H spectrum (Figure S1) and is listed in Table .…”

“…25 For example, the peaks at ∼8.5, ∼7.9, and ∼7.4 ppm, with a diffusivity of 10.0 D (estimated MW 230 Da), can be given a tentative assignment as a three ring PAH (e.g., anthracene or phenanthrene, 178 Da) . 26 The peak at ∼8.5 is not visible in the 2D diffusion plot (Figure 3) because it is smaller than the contouring levels used to display the plot, but it is readily observed at 10.0 D when contoured at lower levels as well as in the raw exponential fit data (Table S3); it is also observed in the 1D-1 H spectrum (Figure S1) and is listed in Table 5. Overall, the data for this region suggests that the largest group of molecules consist of 2-ring aromatics (e.g., naphthalenes), with 3−4 ring PAHs also being prevalent.…”